Internal combustion (IC) engines are widely used for providing mechanical power to drive a variety of devices. IC engines typically include a cylinder in which a fuel-air mixture is ignited, a piston movable in a reciprocating manner within the cylinder due to forces created by the ignition of the fuel-air mixture, and an output shaft driven by the reciprocating motion of the piston. IC engines also typically include a valve assembly for controlling the intake of fuel-air and exhaust of combustion products. The valve assembly is timed for appropriate intake and exhaust during intake compression powered exhaust strokes of the engine. Valve assemblies and the valve actuating mechanisms for barrel type internal combustion engines can be complicated or complex. It remains desirable to provide an improved structure for supporting the valve actuating mechanism and ensuring robust and reliable operation of the valve assembly.